1. Field of the Invention
This invention relates to exercise apparatus and particularly to apparatus suitable for performing weight-training-type exercises.
2. State of the Art
Exercise equipment has more recently been categorized into aerobic exercise machines and anaerobic exercise machines. Aerobic exercise machines include stepping exercise machines, treadmills and exercise cycles. Anaerobic exercise machines include a wide variety of weight-training or strenght-training exercise machines.
U.S. Pat. No. 2,648,540 (Hunter) illustrates a weight-training exercise machine suitable or useful for performing various exercises to develop skeletal muscles with a weight suspended and acted upon by gravitation. The weight acts as the principal resistance against movement of a particular skeletal muscle to develop strength in the muscle.
Other examples of weight-training machines include U.S. Pat. No. 4,316,609 (Silberman), U.S. Pat. No. 4,390,179 (Szkalak), U.S. Pat. No. 3,640,528 (Proctor), U.S. Pat. No. 4,382,596 (Silberman), U.S. Pat. No. 4,964,632 (Rockwell), and U.S. Pat. No. 4,492,375 (Connelly).
Weight-training machines, such as those described in the above-identified patents, typically may be configured to provide a variety of different exercises with the user positioned at different locations. In some cases, the weight-training machines are configured to employ a single resistance structure with cables or other mechanisms interconnected to the single resistance structure. For example, U.S. Pat. No. 4,346,888 (Szabo) illustrates a weight-lifting device having a central weight stack interconnected by a cable and pulley system to a carriage disposed about an upright member with wheels to be movable along the upright member. The device may be operated or reconfigured using the same carriage to provide for different exercises by the user. U.S. Pat. No. 4,492,375 (Connelly) also shows a machine with a carriage movable along an upright member to provide for different exercises at different locations along the vertical member. U.S. Pat. No. 5,135,216 (Bingham et al) also shows a weight-training machine with a carriage movable along the length of an upright member to provide for different exercises for different muscles of the user.
Some weight-training machines have employed an arm or lever which can be reconfigured to provide for different exercises. For example, U.S. Pat. No. 4,763,897 (Yakata) shows an exercise machine with a single weight and cable arrangement interconnecting to a lever which may be reoriented in relation to a platform to provide for a variety of different exercises selected by the user. U.S. Pat. No. 4,621,807 (Stramer) shows an exercise device with weights and counterweights interconnected to a central pulley to which a single arm is connected and reorientable to a variety of different configurations to provide for different exercises by the user. U.S. Pat. No. 4,898,381 (Gordon) also shows a weight-training machine with weight stacks interconnected by pulleys to a variety of levers that may be reconfigured for performing different exercises. U.S. Pat. No. 4,154,441 (Gajda) shows an exercise device involving pulleys and cable with a single weight annually disposed over a central column that slides on that central column.
Many of the weight-training machines of the hereinbefore-listed patents are either very complicated mechanically. In turn, they are difficult to assemble, difficult to operate, and difficult to maintain. Alternately they may be less complicated, but in turn unable to provide a wide variety or selection of exercises that can be repeatedly selected by the user to provide for a regular, repetitive program of weight-training exercises.